#!/usr/bin/env python3
'''
=head1 NAME

Munin Plugin to grab signature count for change.org petition given its ID
You need a valid API key for this petition

=head2 CONFIGURATION

Example:

 [changeorg_signature_count]
 env.APIkey xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
 env.petitions 1727001 1727053

=head1 AUTHOR

(c) 2017 Raphaël Droz <raphael.droz+floss@gmail.com>

=head1 LICENSE

General Public Licence v3 or later

SPDX-License-Identifier: GPL-3.0-or-later

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut
'''

from sys import argv, exit
import sys
import codecs
from os import environ, path, umask
import re
import urllib.request
import json

if len(argv) > 1 and argv[1] == 'autoconf':
    ok = True
    if not environ.get('APIkey') or not re.match('[a-fA-F0-9]{64}$', environ.get('APIkey')):
        print("no (env.APIkey not defined or bad format)")
        ok = False
    for i in environ.get("petitions"):
        if not re.match("[0-9]+$", i):
            print("no ($i isn't a valid petition ID")
            ok = False
    if ok:
        print("yes")
    exit(0)


petition_titles = {}
write_cache = False

if environ.get('MUNIN_PLUGSTATE'):
    petition_cache_names = path.join(environ['MUNIN_PLUGSTATE'], path.basename(argv[0]) + '-petition_names')
    try:
        with open(petition_cache_names, 'r') as f:
            petition_titles = json.load(f)
    except FileNotFoundError:
        pass

for i in environ.get('petitions').split():
    if i in petition_titles:
        continue
    # NB: user-agent's tweak is needed to avoid a 403
    req = urllib.request.Request("https://api.change.org/v1/petitions/{}?api_key={}&fields=title".format(i, environ.get('APIkey')),
                                      data=None,
                                      headers={ 'User-Agent': 'curl/7.38.0' })
    response = urllib.request.urlopen(req).read().decode('utf-8')
    petition_titles[i] = json.loads(response)
    write_cache = True

if environ.get('MUNIN_PLUGSTATE') and write_cache:
    umask(0o077)
    with open(petition_cache_names, 'w') as outfile:
        json.dump(petition_titles, outfile)

# equivalent of passing PYTHONIOENCODING=utf-8 to munin
sys.stdout = codecs.getwriter("utf-8")(sys.stdout.detach())

if len(argv) > 1 and argv[1] == 'config':
    print('''graph_title change.org signature count
graph_args --base 1000 -l 0
graph_vlabel Signatures
graph_category other
graph_info change.org signature count
graph_period minute
''')

    for i in petition_titles:
        print('''signcount_{pid}.label {title}
signcount_{pid}.info Total signatures for {title}
signcount_{pid}.draw LINE3
signcount_{pid}.min 0'''.format(pid=i, title=petition_titles[i]["title"]))
    exit(0)

for i in environ.get("petitions").split():
    req = urllib.request.Request("https://api.change.org/v1/petitions/{}?api_key={}&fields=signature_count".format(i, environ.get('APIkey')),
                                      data=None,
                                      headers={ 'User-Agent': 'curl/7.38.0' })
    response = urllib.request.urlopen(req).read().decode('utf-8')
    print("signcount_%s.value %s" % (i, json.loads(response)["signature_count"]))